The "worm" body plan is a successful one. A head. Bilateral symmetry. Long body. That makes a lot of sense. The head takes the lead and you've got a long, slender body which facilitates success for moving through crevices and such. This has been thought by some to be the body plan for the very first metazoan predators (although not all with the body plan are predators).

Image by Divaholic

There's versatility in feeding and life modes... and the body plan is observed in multiple PHYLA (major grouping) of animals (e.g., annelids, flatworms, etc) and even in other groups which don't primarily have a "worm" like body plan (e.g., aplacophorans in molluscs, sea cucumbers in echinoderms, snakes in vertebrates).

Curiously, there's something ABOUT animals with this body shape that seems to freak people out.

Is it the body shape? Something left over from our "metazoan" brain from a LONG time ago?

People hate snakes. They always use 'mealworms" (actually beetle larvae) on monster and horror films and TV (totally harmless btw). Heck, earthworms are HARMLESS (at least to people) and you can still totally squick most people out by dangling one in front of them!

Image by Mely-o

So what if we looked at worms that are actually PREDATORS? That feed on prey in really graphic ways??

Its Halloween week! Here's FIVE disturbing predatory worms!

Imagining ANY of these as human sized or above would be cause for alarm!

So, I know 46 year old men who STILL get freaked out by Bobbit Worms. Even after all the reassurances and graphic photo evidence PLUS the knowledge that they will never go SCUBA diving in the tropical Pacific!!

Wanna see WORSE than the Bobbit worm?? Let's GO!

2. Ribbon Worms-Long distance Death!

Add caption

Ribbon worms, also known as Nemerteans, are an obscure phylum of worms that are similar in appearance to flatworms (below) BUT one of the big differences is that Ribbon Worms possess a CRAZY long proboscis!

Basically the proboscis is an extended feeding structure used for a FAST grab which in some cases, extends easily 100% of the worms body LENGTH!

Ribbon worms really need to be seen to be appreciated. So here's some video!

Feeding in this worm, is to put it mildly, HORRIFIC. The marine Euplanagracilis is a flatworm that consumes its prey by LITERALLY sucking out its guts, while the prey is still ALIVE!

I'll let the video's author comment:

In this video, Euplana attacks a shrimp-like amphipod by wrapping around its back and completely immobilizing it. Sticking its tube-like pharynx through a segment of the amphipod, the flatworm then consumes and digests its internals--a process that takes about half an hour. Once finished, it abandons the empty carcass and goes into a resting period until its next meal. On the outside, an amphipod that's been eaten doesn't look that different from a normal amphipod...except for the fact that it's, well, dead.

Flatworms that live on the land are seen uncommonly but they're there. And they are mean, vicious predators. I wouldn't have known or even thought to think that, but here we go...

Here is Bipalium, a widely known genus of terrestrial flatworm. Originally from Asia, they've since been introduced all over the world. In their natural habitat, they have these really gorgeous, bright colors....

image by pbertner

Bipalium feeds on earthworms, so much so that they will inspire an immediate escape response whenever they are put in contact with one (see the video below).

Ever see an earthworm literally JUMP in sheer terror? Watch this...

Here's the feeding dance blow by blow... Here's the predator

Image by mistifarang

The worm's head approaches the worm and applies digestive enzymes. It physically begins digesting its prey WHILE THE PREY IS ALIVE...

Image by Amuderick

It digests its meal as a dissolved earthworm milkshake...

Image by Cornell Fungi

BUT its not just the one to one predation which is a concern. TOO many of these predatory land flatworms can actually affect the large-scale ECOLOGY of a region if they devour all the earthworms!

There's marine leeches, terrestrial leeches and of course, freshwater leeches such as the Giant Amazon Leech pictured above! It reaches a length of frakking 18 inches long!! and feed on mammals that happen to stop by to drink...

What are Brachiopods? Brachiopods are actually a PHYLUM of animals. That's right a whole GROUP of animals that most folks have probably never heard of!

image by Herman Giethoom

Brachiopods are a very old, old group of invertebrates with a relatively rich fossil record. They have two shells (and are superficially similar to bivalves, e.g; clams and mussels) but are better known in several other ways...

Brachiopods are one of the few groups of marine animals which live ONLY in the Ocean! (Echinoderms being one of the others...)

Some places you learn about some new mammal, but HERE at the Echinoblog? you learn about a whole PHYLUM of animals in five easy steps!

1. What does the name mean? Brachiopoda, when you break it down: "brachio"= arm and "poda"= foot. Wha? The Arm foot?

The name refers to a structure known as the pedicle. That's the purple stalk bit that is anchoring the animal down to the substrate. This is how the pedicle looksin the group informally known as the "articulate" brachiopods. Arm refers to the muscular arm-like aspect and "foot" to its use (or disuse) in attatching to the bottoms.

The pedicle manifests in two different ways relative to which of the two major groups of brachiopods you are looking at!

One group has been referred to as the "Articulate" brachiopods. And yes; they are very well spoken thank you. ha ha.you have now caught up with the jokes:

Yes. I know the symmetry seems strange and can be oddly difficult to "get" the first time around. Here are some brachiopods...

image by mpjones_007

Image by Alexander Semenov

and here's some clam for comparison (positioned for convenience!)

Image by Royston Vasey

3. What/How do they eat?Brachiopods have a feathery feeding structure called a lophophore! Brachiopods are basicaly suspension feeders. Water flows in and over the lophophore and tiny finger-like bits called cilia pick the food up!

Here's some reality from the very talented Arthur Anker showing the lophophore with the animal's valves open!

And here is the diagrammatic approach that gives you a general idea of what you're looking at.... The animal below has been turned upside down to show parallel orientation with the pic above...

4. In the Paleozoic (roughly 250-500 million years ago), brachiopods were once THE happening invertebrate!

image by David Cartier

Earliest known fossils date back to the Cambrian (600 million years ago-but probably more), but the time of the brachiopod was in the Paleozoic! (bear in mind how vast a time period 250 million years is.. that's MUCH older than humanity..). They dominated in diversity and abundance. This was their "time"... Sadly, most brachiopods underwent a huge extinction at the end of the Paleozoic...

According to the World Brachiopod Database only about 385 species occur today from the ~30,000 described (mostly fossil) ones!!

Many of these species live in out of the way and isolated places...

Here is a gorgeous pic of Coptothyris adamsia from the Sea of Japan

Image by Alexander Semenov

Here is Laqueus californica from Monterey Bay in some pretty amazingly high densities...

and more from Alexander Semenov: Hemithyris psittacea (Rhynchonella psittacea)

5. Geology! Fossil Brachiopod Shells are sometimes replaced by Pyrite! (aka Fool's Gold)In the fossil record, the "shells" (called valves) of brachiopods sometimes undergo a process in which they are replaced with pyrite aka fool's gold!

This makes them golden and sparkly!

Image by jsj1771

Image by E. Sese

Image by JS1771

5a! More Geology Fun! Brachiopod valves are often found in cross sections of rock! Geologists know the value of a good cross section! Brachiopods are VERY abundant in Paleozoic rock. And if you cut through the shells of one you get some pretty distinctive impressions in the rock..

Image by Maitri

Sometimes there are minerals such as agate!

Image by Captain Tenneal

Brachiopod shells can be pretty dense and sometimes you see a lot of them! Sometimes you see some neat rare stuff.. like this soft-part preservation of a lophophore!

Mostly deep-sea urchins found all over the world (many in greater than 1500 m depths-in NZ they range from 100 to 5000 m!), but with some shallow water relatives (aka the Fire urchins, I'll save these for another day)

They often have very sharp and poisonous spines. And yes, the deep-sea ones too...

They "walk" around on the sea bottom with special spines that have hoof like tips

They were described FIRST as fossils and the living animals were found AFTER...

When the animals are alive they look kind of like this:

An Atlantic species by Hankplank

On this purple species from the Pacific (Tromikosoma maybe? this isn't one of the new ones described by Anderson), you can see the white hoof-like spine tips that the urchins use to "walk" along the bottom..

Image by Neptune Canada

Here is a pic showing the oral surface (ie the bottom). The mouth is at center and as you can see it is surrounded by spines with those white "hoof" like tips. These are what the animals use to "walk" along the bottom of the sea floor.

As a result of this "deflated" appearance, they are often called a variety of names: "pancake urchin", "leather urchin", "bag urchin", or "beret urchin." However in Anderson's new paper he feels a new common sobriquet would be most accurate-the Tam O Shanter urchin!!!

Even alive, looking down on one, you can sort of see the resemblance..(note however this is not one of Anderson's new species)

Image by Neptune Canada!

Owen's paper (here) describes a whopping SEVEN species in two genera. That's pretty significant given that MOST of these urchins were described in the early part of the 20th Century/late 19th.

These were all discovered and described by looking at a variety of different characteristics. Some as straightforward as body color as well as spine shape and location. But some characteristics are more subtle. These are the individual pieces of pedicellariae-little claw like structures that are present on all sea urchins..which were studied using a Scanning Electron Microscope to yield distinct shapes...

Fig. 28 from Anderson 2013

He also reviewed the many echinothurioid urchins in the New Zealand waters, in addition to the seven known species, Anderson described/reviewed a further nine species (7 were new) culminating in a count of some 16 species of these urchins in the region!, including this beauty... Araeosoma thetidis!! (described by Hubert Lyman Clark in 1909)

Shallow water echinothurioid urchins are "proper" fire urchins. As opposed to these other "fire colored" spiny urchins, such as Astropyga which are diadematoid urchins. A completely different group!!

"Spiny" urchins are distinguished by the presence of an Anal Cone. See that white bulb on top? THAT is where the poop comes out! You don't see that in "proper" fire urchins as we'll be seeing.. Note also that the spines are much longer.

And if its not clear by now, YES. They're pretty damn venomous. My understanding is that its very painful.. but typically not lethal.

and they certainly do seem like they do, don't they??

Image by Bruce Magun

Image by Daniel Stassen

Close ups! showing some of the brillaint colors, spine patterns and etc.. I suspect most of these are Asthenosoma varium

Image by MerMate

Image by Daphna130

Image by lupopeye

Image by maractwin

Image by Nick Hobgood

Image by B. Maither

Image by Russell Taylor

Here's some differing species from around the Indo-Pacific

From the Red Sea, Asthenosoma marisrubi with a more mellow look...

Image by Key of Life

Here are the spines..still basically the same but different color and slightly different shape..

Image by Le Congre

Asthenosoma spp. showing many different colors...

Image by S1mon Mar5h

Image by Clark Chang

Image by Jesse Claggett

Image by Richard Barnett

What's even MORE interesting? These urchins have tiny critters which live as commensals(?) among the highly poisonous spines! (this neat vid also shows a LOT of close up details)Urchin Riders from liquidguru on Vimeo.Some of the little buggers actually "hollow" out a space, clearing out spines where they can live! You can see the bare patch on this one...

Image by Klaus Stiefel

In addition to all the various crustaceans, Amazingly. Here is a benthic ctenophore (which I've written about here) ON A FIRE URCHIN!! (the white blobby bits are the feeding tentacles) Mind. blown!! and incidentally.. a likely first occurrence recorded....

A few words today about SYNAPTID sea cucumbers! (i.e, Family Synaptidae). These are a family of unusual sea cucumbers which are observed in shallow/SCUBA depth waters in the tropics! There are over 120 species of synaptids which occur primarily in the Indo-Pacific.

Synaptid sea cucumbers move pretty actively via peristalsis (i.e., body pulsates in a manner similar to that of worms. They seem to have lost any external manifestations of tube feet..

Image by Jay Dryden

Synaptids have a well-developed array of feather-like feeding tentacles they use to move organic food into their mouths. Here's a video that shows one alive and kicking!

As the video shows, synaptids move along the bottom in a snake-like-fashion using their tentacles to move food into their mouth as they move as this species (Synapta maculata) from Lembeh Strait in Indonesia is doing..

Image by Bernard DuPont

This shows how long these get.. Some reach 6 FEET long...

Image by shamsulazar

Some are decoratively patterned!

Image by ania115

But while some species are huge and massive, others are tiny and form HUGE aggregations...

In Synaptula spp., you'll often see hundreds of them on a single sponge! What I like to think of as a veritable city of sea cucumbers!

See all those wormy white things on the sponge? THOSE ARE SEA CUCUMBERS! (the genus Synaptula sp.).

image by Enice Khoo (mermate)

Another dense sponge colony overrun by Synaptula!

image by Bernard DuPont

Here's a less populous one..

image by Tom Puchner

More!

image by Alfonsator

some of them crawl around on purple sponges!

Image by Wild Singapore

image by Wild Singapore

This is not the same sponge colony but a close up of a different one.. it gives you an idea of what's they look like (close up).

image by Rob Jeff

But what are they doing? Presumably this posture of them reaching upright into the water is feeding,i.e., taking advantage of the water currents. Sea cucumbers living on a sponge is actually a pretty convenient place to live.. as sponge filter water, they likely accumulate all sorts of potential food particles that Synaptula can take advantage of...

Image by Richard Ling

Amazingly, this is only the TIP of the iceberg where these animals are concerned..but that will have to wait for a future post!

December Greetings! As we get into the holiday and Christmas season, I always get certain questions which pop up around this time of year, asked by the public. One of the common ones I receive around now is (paraphrased)

"Where do those starfish and sand dollars on holiday decorations come from?" Usually followed by "Are they alive?" and etc...

So, let me take a trek through several recurring photos of holiday decorations and show you species by species how they compare.

A general rule about echinoderms used in decorations: WHAT YOU SEE ARE NOT SHELLS, THEY ARE MUMMIES (dried endoskeletons).

Image by Werner Wittersheim

A bit of a refresher on basic echinoderm anatomy. All of the distinctive features one sees in echinoderms- spines, tubercles, the various shapes and etc. are covered by epidermis, in other words, SKIN.

So, yes, in order to get one of the starfish dried and made into a wreath? It has to be killed. (that's one of the questions I get about these by the way...)

So unlike say, shells which are secreted outside or independently of the animal's body, echinoderms have an internal support that is analogous to the skeleton in vertebrates. Their tissue is actually infused into this skeleton.

I've said this before many times. Here and here. I've always found the whole concept of putting echinoderms onto holiday decor as kind of macabre unless you're that guy who puts skulls and dead, dried frogs on your Christmas tree, which is perfectly fine....

1. "Knobby Starfish" Holiday Wreath

This is one, I've been seeing around is adorned with large, "Knobby Starfish"

These are Protoreaster nodosus, a species which occurs in the Philippines, Singapore, and all throughout the North-Central tropical Pacific.

Image by Ria Tan (Wild Singapore)

Image by Pau Estrada

Protoreaster nodosus is an abundant and easily encountered species where it occurs. It is harvested in several places for tourist and gift making decor. A whole industry is oriented around fixing (ie treating with formalin), drying and exporting dried starfishes. I've briefly discussed this here and here

2. Pisaster ochraceus & the "Coastal Wreath"(thanks to Gail for the tip!)

Thanks to the wonders of the Internet and directed marketing, I clicked on the link to this item ONCE. And it now shows up on ALL of my social media and other shopping pages...

The picture actually shows up on several different gift and other sites, which I'll decline to name. But two species are observered here. the starfish is Pisaster ochraceus aka the Ochre Star from the Pacific NW coast and the sand dollar Mellita (prob. Mellita quinquiesperforata ).

Its not unusual for Pisaster to turn up dressed up as any number of awful, tacky holiday decorations

Here again, is a pic of the animal alive to remind you of the contrast...

Another commonly encountered species in holiday decorations. Sand dollars, especially these species have the most "benefit of the doubt" because its not unusual to encounter their dead skeletons as beach wash.

Although one has to wonder how much collecting one needs to have enough to create a regularly marketable wreath such as the ones I've been seeing marketed on the Internet...

I'm pretty damn amazed at just how WIDESPREAD these get via the tourist industry. I've literally seen these sand dollar shipped across the country and across the WORLD for sale at tourist shops.

Here is what they look like with all the original spination and such...

and we even got video!

5. Echinometrid? "Sea urchin tree"?

Maybe Echinometra from Australia? Not sure. Like sea urchins, the tests can be gotten as beachwash.. but not regularly. So, I'm thinking these were likely harvested...

Image from NOAA photo library

The websites for "urchin trees" and such were running these items for anywhere between 70 to 150.00. But cripes! 150 dollars for sea urchin tree???

So to recap:1. Starfish decorations are mummified remains of living animals, which had to be killed in order to get you a holiday wreath. I wouldn't lick them.2. Many of the species used in these industries from the tropical Pacific are probably not sustainable fisheries.3. Personally, I just think decorating starfishes like Santa Claus is tacky. So, please. just stop. Use sea shells or give people candy. People like candy.4. Sand dollars are okay. Still possible to kill them for use as decorations. But also possible that they were collected beachwash.5. Good grief. Who pays 150 dollars for holiday decorations made from beachwash??? or mummified starfish remains??? You know what's good for 150 dollars? chocolate.Send to the Echinoblog. Or charity. charity is good.

Here's a nice image of Astropecten indicus from Singapore, illustrating the animal next to the star-shaped impression it makes in the sand.

Image by Kok Sheng

Here is an excellent photo sequence of a species of Astropecten from Iran, showing a full range of sitting on the sand and burying itself.

Image by Hamed Saber

Burial in Astropecten can be quite rapid. It accomplishes this via a combination of its pointed (rather than suckered) tube feet in conjunction with its many spines which are moveable and are used to help push itself into the sand. Astropecten is among the fastest of known starfish. Image below of an Astropecten from Singapore.

Image by Wildsingapore.

Pictures are nice. But why stop there? Here's a quick 30 second video of Astropecten from Singapore burying itself and vanishing before your very eyes!

Which famous Simpsons gif meme does Astropecten remind you of?

This one is probably one of the best videos of Astropecten burying and reburying itself. A video from the Enoshima aquarium of A. polyacanthus.

Although they dig, they are not, strictly speaking, infaunal. They live buried right under the surface of the sand...

image by Bill & Mark Bell

Where, they are often digging through the sediment trying to find goodies to eat, such as this clam. But really whatever they find, they will swallow and devour. Note that Astropecten and its relatives LACK an eversible stomach (that you might see in other starfish). So they literally can ONLY swallow their prey.. This image is fr. A. aurantiacus in the N. Atlantic somewhere..

As I mentioned, Astropecten occurs widely around the world. And is quite diverse. Here is Astropecten articulatus from Georgia (south coast of the US)

Image by Alan Cressler

Astropecten sp. from Singapore. Cool racing stripes!

Image by Wild Singapore

Here's a pic of Astropecten latespinosus from Japan

Image by Yoichi Kogure!

The substrate/sediment type can vary also.. Some live in very fine sediments, such as this Italian Astropecten, possibly A. irregularis

Image by comunerimini

Astropecten aurantiacus in sandy sediment...

Image by Archipelagos Institute of Marine Conservation

Whereas others live in fairly coarse, sandy type sediments.. such as this Astropecten bispinosus from Greece.

Image by sarsifa

Astropecten sp. Not sure where this was taken..I think the Mediterranean? But again, coarse sediment.

Image by Dimitrious Poursanidis

Image by Dimitrious Poursanidis

What's that you say? You wanted to see more fabulous video of Astropecten from around the world burying themselves in sand? YOU GOT IT.

Happy Holidays! Who loves a Christmas tree decoration? And has broken one in their lifetime?

Well, in the real world, we get to see LIVING glass (or sometimes chalk) boxes that might pass for ornaments! But you need to shoot electrons at them to get something like a similar effect! Scanning Electron Microscopes are the gift that keeps on giving!

First some phytoplankton from the Southern Ocean (Antarctica and thereabouts) from Robert Johnson! Actual size of most of these is probably VERY small on the order of mm or less..

I believe these are diatoms called Chaetoceros

I should recognize the next few. Some have indicated that they are silicoflagellates..

Here is a diatom called (appropriately) Skeletonema. This one occurs in Florida waters..Image by FWC-Fish & Wildlife Research Institute

But for some reason, people NEVER know enough about them. Case in point-one of the most amazing but, I think, underutilized resources available for people studying taxonomy and biodiversity: The Biodiversity Heritage Library! (and note the button for donations!)

What are they? You can certainly go and read all about them at their Wiki here. But simply put, they are a massive digital, online archive of OPEN ACCESS (that's the academic word for "free") taxonomic, naturalist and other literature which pre-dates copyright, or is by definition freely available to everyone (such as federal government materials) and has been made available via the Internet to ANYONE who wants it.

This helps a LOT of people who are looking for VERY old and RARE taxonomic monographs which might ONLY be available from either a handful of Natural History Museum libraries OR a very expensive used book dealer.

For example, let's take the work of starfish taxonomist, Walter K. Fisher former director of Stanford University's Hopkins Marine Station "back in the day" during Ed Ricketts time (circa 1930s)....

He was a GIANT in the taxonomy of starfishes. And published more genera and species of starfish than ANYONE. Not an exaggeration. He published 566 taxonomic names, including 312 species which are still accepted today. These include almost ALL of the deep-sea starfishes from Hawaii, the Philippines, the Celebes and many more in the North Pacific.

Prior to the BHL, these books were vintage. 1906. 1911. 1919. It took me many, an hour scrubbing tanks and hauling boxes to get the 200 bucks it cost me to buy my first copy of Fisher's "Asteroidea of the North Pacific". Now, thanks to the BHL, you can get it as a freely available download!

But what's the catch? Well, the thing is they kind of did too good a job! There is SO much material available that actually finding the stuff that is useful for certain people requires a bit of navigation and experience. Some monographs are part of other series that weren't distinguished. So herein, I make it easy for the interested starfish taxonomy student.... Here's a bunch of his big monograph/books (click to go):The North Pacific Asteroidea MonographsFisher 1911-Asteroidea of the North Pacific. Pt. 1. Phanerozonia and Spinulosa

What makes Sea Cucumbers such desirable housing? While there's no immediately clear data on the topic, it seems to be important that sea cucumbers are all composed of a soft, edible yet durable, tissue. So, maybe a good house that these protects and feeds?

Note also that some common names refer to different KINDS of ophiuroids. "Brittle stars" tends to refer to the more conventional types of ophiuroids, such as the ones here and like those above.

On the other hand, "basket stars" tend to be highly branched and with lots of fleshy arms. These sometimes also get called "serpent stars" if they have only 5 arms.

So terminology is pretty straight forward. Brittle stars AND Basket stars are BOTH different types of ophiuroids (technically.. members of the Class Ophiuroidea).

1. How many species of brittle stars are there??

Answer: As of the 2013 paper there were 2,064 recognized species of brittle stars known in the world. I know for a fact that there have been manymore described since then. So, by the end of 2014, I'm guessing we will see closer to 2,075 or even 2,090 species!

In terms of species, brittle stars are by far the MOST diverse of all the living echinoderms. Sea stars follow up in 2nd place (n=~1900 species), followed by the sea cucumbers (Holothuroidea, n=~1250), then sea urchins and sand dollars (n=~950 species) and finally, the living crinoids (n=~600 species).

This has never been a big surprise to invertebrate zoologists. Brittle stars live EVERYWHERE. Under rocks, in the mud, on corals, under corals.. even ON JELLYFISH.

2. How many different KINDS of brittle stars are there?

Fig. from Stohr et al.

A more accurate question might be "How many families of brittle stars are there?" This basically represents how many kinds of basic body plans or GROUPS of brittle stars are there? A smattering of the different kinds of brittle stars is represented above.

Here is the table from Stohr et al's paper...

There are 270 genera in 16 different families. So, there's a fair diversity of body plans within the Ophiuroidea but not as much as say, in starfish (which have 370 genera broken up into 36 families). So the bulk of diversity in brittle stars appears to be at the species level. That sounds consistent with their apparent overall strategy of diversification into whatever habitat or niche seems to make itself available, given how many places on the marine bottoms they can be found. There's a high number of species that avails itself of ecological niches.

But more on that below...

3 Which groups of brittle stars are the most diverse??

The MOST diverse of brittle star families? The Amphiuridae! An example shown above, courtesy of the wonderous Arthur Anker! As of 2013, there were 467 accepted species.

Amphiurids are burrowers and diggers. They find their way into mud, sand, any kind of loose sediment that they can shelter in and under. Once dug in, they throw their arms up through the sediment and out into the water to "fish" for organic particles and other food.. As shown here...

Although amphiurid brittle stars vary in size, many of them are tiny, tiny little critters that fit easily into cracks, crevices and nooks in rocks or other underwater habitat. They live EVERYWHERE.

And the 2nd place winnah??? The Ophiuridae, with 344 species

Ophiurids truly are diverse. They live in the deep-sea, in the shallow tropics, and in temperate waters. There's a LOT of them and often times they are very abundant, often comprising a HUGE amount of biomass where they are found.

Stohr and colleagues have very nicely mapped out the number of species by different biogeographic zones around the world. Their breakdown as follows:

831 species! HIGHEST diversity is in the tropical Indo-Pacific. 400 species! North Pacific! The temperate/cold-water band including North America and Asia.350 species! The South Pacific-the temperate water zones around Australia, New Zealand and etc.333 species! The West Atlantic.319 species! The Indian Ocean! Examples of new species from the Indian Ocean? Here. 237 species! The North Atlantic199 species! South Africa183 species! East Pacific123 species! Antarctic120 species! South America 73 species! Arctic

What's MOST interesting about these? When one looks at the species diversity by depth, the MOST diverse areas? the Indo-Pacific, South and North Pacific? A significant amount, sometimes more than 50% of the diversity of these faunas is from the deep-sea (>200 meters!).

Most sensible scientists would agree that ophiuroids and asteroids diverged at some point in the Paleozoic with modern-looking brittle stars appearing sometime in the mid to late Paleozoic, some 440-485 million years ago or so. So, yes. Brittle stars have a very old lineage as do most echinoderms. Older than dinosaurs and certainly older than humans.

But most "good" fossils of brittle stars are largely observed in Mesozoic rocks. There are actually quite a lot of brittle star fossils out there but many of them were identified using pretty substandard taxonomy by geologists using out of date identification concepts (long story)..

And so, long story short, only now are we actually assessing fossils and looking at their real significance in the history of marine invertebrates.

Toxopneustes! aka the "Flower Urchin" is one of four species of Toxopneustes (all of which occur throughout the tropical Pacific). One species, Toxopneustes pileolus is one of the most frequently encountered and as such, this is the name most often applied to sea urchins that have the distinct appearance (as seen above).

Toxopneustes literally means "toxic foot"undoubtedly alluding to the MANY venomous pedicellariae that compose the animal's appearance. I'll explain "pedicellariae" more below..but just so you know what I'm talking about? ALL of those yellow circles and traingles in the picture above? Those are tiny little claws and each one of them is toxic. So be careful around these guys..

Toxopneustes has all of the other stuff that you see in other sea urchins, such as spines and tube feet.

The circles and triangles below are pedicellariae. Round means the pedicellariae are "open" and the triangular ones indicate the pedicellariae are either closed or are closig. The brown rods below that kind of look like toothpicks? Those are the spines, which are actually not themselves toxic (as far as I've read).

Toxopneustes has been known for quite a long time. The genus was described in 1841 by Louis Agassiz, so we've had some time to think about it.

This then, is the puzzle. Why do we seemingly know so little about it?? As we'll see, it has a formidable reputation as a highly venomous species and its a prominent tropical sea urchin but really, a lot of what we know essentially boils down to this....

1. Toxopneustes pileolus displays covering behavior. I have discussed and blogged about "covering behavior" in the past (here). Toxopneustes is a "collector" urchin, which means that it shows the curious behavior of adding rocks and other debris using tube feet and/or pedicellariae to cover over itself.

Although the reasons are not well understood, it is thought that this could serve to protect the urchins from ultraviolet rays. In some cases with other urchins, its thought that the materials serve as defense, but given the highly venomous pedicellariae on this species, I kinda doubt that's the case here.

2. Flower urchins spawn in the Spring and "undress" their covering materials to do it! This one is self-evident since all animals have to reproduce. And most echnoderms spawn externally. But it was only recently in a paper by Andy Chen and Keryea Soong in Zoological Studies in 2009 which showed that they showed Toxopneustes pileolus"release" all of the materials obtained via their "covering response" before they spawn.

Here is Figure 1 from Chen & Soong 2009. Showing on the left, a "covered" urchin and then on the right an urchin "uncovered" and spawning.

The poison is served via the pedicellariae which are all of those triangular and circular structures that you see on the surface of the urchin.. Here the pedicellariae are all agitated. How can you tell? Note that they are all triangular instead of round. That means they are closed and have been recently agitated...

Here is more of a closeup of each one. Each with a stalk connecting them to the body. They are round when open and more triangular when closed.

Here's a diagram of one, showing the hard parts within all of the softer covering. Basically, each one is a claw that injects poison.

And below is a nice SEM image of a similar kind of pedicellariae from the East Pacific species. Toxopneustes roseus showing it in more detail.

Well, strangely enough, there are very few modern (read-quantiative) accounts of how toxic/painful/ potent Toxopneustes poison can be. However, I did locate an older account from 1935 by Dr. Tsutomu Fujiwara at the Hiroshima Zoological Laboratory in Japan who reported his experience with being stung by one (italics and paragraph break are mine) in Annotationes Zoolgicae Japonenses 15(1): 62-68

On June 26, 1930, while I was working on a fishing boat on the coast of Tsuta-jima in Saganoseki, I scooped up with my bare hand an individual of the sea-urchin which had been carried up by a diver with a fishing implement on the water surface from the sea-bottom about 20 fathoms in depth, and I transferred the sea-urchin into a small tank in the boat. At that time, 7 or 8 pedicellariae stubbornly attached themselves to a side of the middle finger of my right hand, detached from the stalk and remained on the skin of my finger.

Instantly, I felt a severe pain resembling that caused by the cnidoblast of Coelenterata, and I felt as if the toxin were beginning to move rapidly to the blood vessel from the stung area towards my heart. After a while, I experienced a faint giddiness, difficulty of respiration, paralysis of the lips, tongue and eyelids, relaxation of muscles in the limbs, was hardly able to speak or control my facial expression, and felt almost as if I were going to die. About 15 minutes afterwards, I felt that pains gradually diminish and after about an hour they disappeared completely. But the facial paralysis like that caused by cocainization continued for about six hours.

Other accounts have detailed stopping oyster hearts, and contraction of smooth muscle, including cardiac (heart) tissue. Some accounts of Toxopneustes have stated that swimmers have drowned following stings but I wasn't able to verify an account of this.

5. What we DIDN'T know about commensal crabs (but do now, thanks to the internet!)

That's a bit of a cheat. We DID know that commensal crabs live on Toxopneustes. Apparently, these striped little fellows are called Zebrida adamsii. The name "Zebrida" undoubtedly hailing from the zebra-like stripes on the animals' body.

Here's one living on Toxopneustes pileolus with some eggs!

But what is REALLY interesting is just HOW these crabs live on the urchins! Look at the video below.They actually CLEAR off the pedicellariae and spines and live on a bare patch of the animal surrounded by all the poisonous pedicellariae and etc.

Questions!? How far/how long do they hitch a ride?Do they feed on the tissue from the tube feet and pedicellariae? Are those "bare patches" long term? Or are they only from acute attacks? (those crabs seem to be pretty comfortable there!)Are the crabs as well camoflaged as they seem?Interestingly, note also that the pedicellariae are all open and seemingly comfortable. Does that mean they are pretty cool with the crabs living on them that way? What do the urchins get out of it?IS Toxopneustes REALLY the world's most venomous sea urchin???Someone go find out and tell em' the Echinoblog sent ya! (unless you get stung-then uh.. it wasn't)

I started this blog in 2006 without a really good idea of what I was getting into.. and it was my big Sea Pig post (here) that really gave me an idea of just how far a blog that specialized on echinoderms (of all things!) could go.

So, its now been three years and I've had a chance to look at some numbers and trends. This has given me a chance to see exactly HOW my sea pig post has presented these animals into the public eye.

Now bear in mind, that the term "sea pig" actually refers to sea cucumbers in the family Elpidiidae, mostly in the genus Scotoplanes but several genera are similar and fit the bill pretty easily.

Prior to the late 20th/early 21st Century, before we had video and crisp pictures of these animals in their natural habitat, the number of people who even knew these animals even existed was something you could count on two hands. This included a small number of echinoderm taxonomists (no more than 6) and deep-sea biologists who had perhaps seen the dead ones or perhaps pictures from towed underwater cameras.

As the early 2000s rolled around, some pics and etc. rolled around. People were discovering some of the weird and crazy stuff that lived in the deep-sea. Giant Isopods and all of the "big stars" of a deep-sea biology book were slowly coming to life!

In 2009, I came across an unusual spike in readership (probably from a Facebook quiz) that was focused on a "sea pig" I had posted from a blog about a scientific meeting on image analysis. I rapidly figured out (thanks to some help from friends on Facebook) that people had seen this strange beast and wanted to know what it was. So, I took the July 4th weekend and wrote that up and posted it!

Here are the Google Search trends graph for "sea pig"and the term "sea pigs". Basically, there is a HUGE spike in hits for July 2009 (when my sea pig post went up, followed by the Animal Planet post), and a significantly greater interest afterwards...

What do the numbers mean? Here's the explanation from Google Trends:

The numbers on the graph reflect how many searches have been done for a particular term, relative to the total number of searches done on Google over time. They don't represent absolute search volume numbers, because the data is normalized and presented on a scale from 0-100. Each point on the graph is divided by the highest point, or 100. When we don't have enough data, 0 is shown.

Its fascinating to see how outreach and social media have affected the perception and awareness of a weird, little sea cucumber, which frankly, nobody gave a damn about throughout most of the 20th Century. And I'll be honest, research on this species has not perceptibly jumped but perhaps that's just a matter of time as inspiration and funds dovetail...

Where has the "concept" of sea pig gone? How have they entered into the culture?

3. Sea Pigs were on OCTONAUTS! (and were scientifically accurate!) My thanks to "Skymouse" who sent me this link!

4. and of course the famous "voice guy" from Buzz Feed and so on Ze Frank did one of his famous "True Facts about the sea pig" videos!5. and MOST recently, Kronos Quartet has been inspired to compose music from/about/by Sea pigs??

Did I directly participate in getting sea pigs on Octonauts? No, but would Octonauts have a show featuring sea pigs without my blog back in 2009? Who knows? But its nice to know that contributions and/or influences from the Echinoblog can be seen in a variety of places.....

Have you seen some new art/statue/show/pop culture reference to sea pigs? Let me know! I'd love to continue seeing how sea pigs become part of popular culture..

I am travelling! I am enroute to Tokyo, Japan where I will be spending about a month studying the starfishes of Japan at the National Museum of Nature and Science in Tokyo!! which is approximately the equivalent of the Smithsonian's National Museum of Natural History. In other words, their country's national repository of natural artifacts and biodiversity!

Today i recap some of my past articles on echinoderms in Japan! (but next week I will blog about the trip!)

The trip begins! At the crack of dawn and off to the airport for an 8 AM flight from Washington DC!

At the "jumping off" point in San Francisco.. As if to herald my arrival in Japan! An exhibition of Japanese toys! Many provided by my friend, Ultraman fanatic Mark Nagata! These are on display at the United Terminal on my way to the flight...

Some nice art by Shotaro Ishinomori of Robot Detective K!

The flight over the Pacific is a long 10 hours. But the scenery is nice enough. The flight arrives as the sun sets in Tokyo!

So, yes. A LONG day, where I literally saw the sun rise in the west and sun set in the east!

The National Museum of Nature and Science!

Why am I visiting? As part of my research, I am involved with a grant, funded by my colleague Dr. Toshihiko Fujita to study the asteroids (aka sea stars, starfish) of Japan!!

The National Museum of Nature and Science is basically the Japanese equivalent of the Smithsonian's National Museum of Natural History. It is a repository of artifacts, specimens and other materials that are part of Japan's heritage. The original material from which new species are described is kept here as well as further records of species throughout Japan.

Much of their collection is from deep-sea habitats! Since I work primarily on deep-sea species my expertise was naturally called upon!

The NMNS has a NEW facility in Tsukuba, Japan outside of Tokyo. Their collection room is barely a few years old and is literally spotless!! It is shiny and amazingly clean!

The specimen jars are kept in these protective plastic boxes, which protect from earthquakes, dust and other common problems associated with museum storage.

But, Japan is a land of contrasts! So, alongside the brand new 21st Century is the old 19th and 20th Century!

Here is a specimen of Bathynomus! A giant isopod from Japanese waters in an old display jar...

and Colossendeis! A giant deep-sea sea spider....

Perhaps MOST interesting, was this building! This is the EMPEROR's Natural History Collection!! Emperor Hirohito, known as Emperor Shōwa in Japan(1901-1989) was a respected marine biologist, who studied hydrocorals and hydroids, tiny animals related to sea anemones and jellyfishes.

I've gotten the impression from some folks who believe/perceive that scientists who travel abroad (or anywhere really..) are somehow living in the lap of luxury. I've lived across the board when traveling on the "science dime" and at least, for folks like me, fine dining and luxury hotel rooms are for a different class o' people...

so here is a little bit on Japan but also some insight on how I live when I travel. I am not atypical for the kind of science that I do...

1. Living the Scientist's Travel Life. By now, I'm kind of a seasoned scientist. I've got a PhD, I'm older and less inclined to sleep on people's floors. Plus, when I travel, my status as a professional (and my personal preference) leads me to a proper room with a bed and so forth.

But when I was a grad student/younger post-doc I "paid my dues" and ran the gamut: I shared cheap hotel rooms with two or three others (sometimes I knew them), lived at the YMCA in the bad part of town, slept in Greyhounds, and lived my share of research visits in roach-infested rooms without air-conditioning in the middle of the summer and slept in fishing vessel sleeping quarters with a smell that never goes away....

So, its nice to get a simple, clean dorm room like this one. My thanks to the NMNS for having decent (and affordable) dorms for their visiting researchers! Yes. There's even a washing/drying machine in there! Fancy! (and for those concerned about expense, this room was supported by the NMNS, no US tax dollars are at play...)Here's one of my rooms when I lived in Paris. Also nice. A bed. A window. Some closet space. Its nice to have a conveniently placed bathroom with toilet AND shower! (not always the case!)

And just for the big compare-my quarters aboard the R/V Laurence M. Gould. Clean, cozy and dry. Given how busy you are on a ship, you're lucky to be in them...

Back to Japan...

Tokyo's living arrangements come with a slightly different set of cultural norms than what we encounter in western societies.

For example, one leaves ones shoes at the door outside the main residence...This typically involves trading out for a pair of slippers, but as an American my feet are pretty big, so I end up walking around with socks!Slippers are special to special rooms! Here in the restroom, you actually have a pair of special slippers JUST for using in the "water closet" (or W.C.) /toilet room.

These are toilet slippers. For use ONLY in/around the toilet. Its actually considered an awkward faux pas to be wearing these outside of their designated area.

My room is pretty normal. Nothing fancy. But in the main museum building (and in many restaurants and professional places) you get the famous Japanese electric toilet!

Yes. Everything you've heard about! The seat is heated. The control panel has standard buttons that basically launch a stream of water out of the bowl to uh... rinse down all of those troublesome bowl-side trouble areas! Low stream! High Stream! Yes. That means your toilet not only has a control panel, but an electric plug into the wall. WOO!

Sadly, Echinoblog is not brave enough to try the bidet function on the toilet, so data on that sensation will have to wait!

2. FOOD!!

So, yes. There is delicious and distinctive cuisine in Japan.. the gyoza ("pot stickers" if you are familiar with the Chinese version) are delicious (and one of my favorite foods)

RAMEN in Japan is simply amazing. This bowl of tonkatsu (pork ramen) was worth every agonizing minute of my 18 hour flight...

But truth be told, the thing that is the MOST curious and interesting is the unusual array of food at your local 7-11! Yes. On many days, I shop and eat here. Budgets being what they are...

7-11 in Japan is an amazing place that is barely recognizable as the same sort of shop! FRESH food every day. Clean! They leave the booze out in the open! Courteous clerks! Clean stores! Items arranged neatly and with proper rotation! No year old hot dogs!

Some of the cool candy and foods to be found there? GREEN TEA KIT KAT! (no chocolate Kit Kat to be seen!)

But what's more amazing? These fresh Pancake things that are already FILLED WITH MAPLE-SYRUP like stuff!! (Happy Pancake Day!)

MMMM.......

And you know what ELSE you can buy at 7-11?? Little books on DEEP-SEA BIOLOGY!!

And finally... someone at the Museum treated me to this neat, little thing: A Shrimp chip WITH AN ACTUAL SHRIMP!!

Yeah, there wasn't much biology this week. But those pancake things are neat aren't they?